Antenna heating



P. S. CARTER ANTENNA HEATING May 5 1%36.

Filed Aug. 9, 1950 s Sheets-Sheet 1 INVENTOR P. s. CARTER ATTORNEY May 5 1936. 5, CARTER 2,39,295

ANTENNA HEATING Filed Aug. 9, 1930 3 $heets-Sheet 2 l I I I l I l l l l I L INVENTOR P. S. CARTER ATTORNEY P. S. CARTER ANTENNA HEATING May 5, 1-936.

Filed Aug. 9, 1930 3 Sheets-Sheet 3 INVENTOR NEW v P. s. CART ATTORNEY Patented May 5, 1936 UNITED STATES PATENT OFFICE ANTENNA HEATING poration of Delaware Application August 9, 1930, Serial No. 474,086

2 Claims.

This invention relates to antennae and has as its main object the provision of new and useful means for melting sleet from antennae by supplying electrical heating energy thereto.

Still a further object of my invention is to provide in an antenna having conductors excited cophasally with high frequency energy means for serially supplying heating energy to the conductors and yet allow of the required cophasal high frequency excitation of the same.

In the event that the antenna system comprises an antenna structure and a similar reflector structure, a further object of my invention is to provide for the heating of both antenna and reflector by supplying heating energy simultaneously to both structures.

I Although it is desirable to energize both an antenna and reflector simultaneously with heating energy, a large enough supply of energy to do so may not be available. Under such circumstances, it is a further object of this invention to provide a system wherein the antenna and reflector may be separately energized with sleet melting currents.

As required by law the present invention is defined with particularity in the appended claims. However, it may best be understood both as to its structural organization and mode of operation by referring to the accompanying drawings, wherein Figure 1 illustrates a form of antenna system comprising an antenna and reflector without the provision of sleet melting means.

Figure 2 illustrates the manner in which the apparatus shown in Figure 1 is to be modified when sleet is to be melted from transmission lines antenna and reflector at one time without inter-- fering with continuous high frequency operation of the antenna, and

Figure 3 is illustrative of an antenna and reflector system wherein the antenna and reflector units may be heated separately.

Referring to Figure 1 there is illustrated an antenna system such as I have disclosed and covered in my United States Patent No. 1,974,387, granted September 18, 1934 comprising an antenna structure A and a reflector structure R. Each of the structures comprise two angularly disposed conductors 2, 4, long, relative to the working wave length and open-ended so that standing waves are produced thereon by reflection phenomenon. In a plane parallel with the conductors 2, 4, in order to concentrate in a direction perpendicular to the plane of the diverging conductors 2, 4, the beam of transmitted energy, or in the case of reception, to increase the directivity of the system in that direction, additional open-ended diverging conductors 6, 8 are provided which are tied to conductors 2, 4 by connecting conductors or Wires l0, l2.

The system so far described is connected to high frequency apparatus l4 either receiving apparatus or transmitting apparatus, through an impedance matching circuit I6.

As the antenna and reflector are placed apart, for best action, along the apices of the angle formed by conductors 2, 4 an odd number of quarter wave lengths, the branch transmission line I8 as indicated, should be an odd number, of quarter wave lengths long. The transmission lines 20 feeding the reflector and antenna structures, are terminated by conductors or short circuiting strips or jumpers 22; and, substantially a quarter of a wave length away from jumpers 22 conductors 24 are connected for connection to tuning loops 25 having jumpers 2S thereacross. Adjustment of conductors 22 will properly terminate lines 20 and cause at the connection points of conductors 24, a desired energy flow from lines 20 into conductors 24. Adjustment of conductors 28 provides for the tuning of the antenna and reflector structures.

Either of the structures may be considered as an antenna and the other an energized reflector therefor, as the directivity of the system depends upon the relative phase excitation of the conductors forming the antenna and reflector. As shown, as the standing waves on structure R. would be 90 degrees ahead in phase of those of antenna A the system would be predominantly unidirectional in a direction from the reflector towards the antenna, if the system were used for transmitting, along the bisector of the angle formed by the parallelly angularly disposed conductors 2, 4, and 6, 8.

In order to provide for the heating of the various conductors involved, I change, as shown in Figure 2, the conductors of each tuning loop 26 to consist of pairs of wires 30, 32 and 30', 32' and I tie the wires leading to each unit consisting of conductors 2 and 6 or 4 and 8 together for radio frequency currents by means of suitable blocking condensers 34. The conductors l0, I2 are broken by condensers or insulators 36, and the open ends of the conductors 2, 4, 6, 8 are connected together by jumpers or conductors 38.

The cophasal excitation of wires 2, 6 and 4, 8 of the units will not be affected as the conductors 30, 32 and 30', 32' act as single wires for radio frequency currents. Similarly, the addition of jumpers 38, as they connect points of like polarity result in the currents flowing from the ends towards the center of the jumpers. Thus radiation is negligible and the system acts as though the antenna conductors were absent. Radiant action of the jumpers 38 being negligible will not affect the system as a whole.

Heating energy is supplied from a power transformer 40, supplied with relatively low frequency alternating energy, and applied through radio frequency choke coils 42 to transmission lines I8, 20 through the impedance matching circuit l6 as well as the transmission line 44. To prevent short circuiting of the heating energy away from the radiant responsive structures consisting of the diverging conductors, transmission lines 20 are terminated by condenser 31 which are effective short circuits for radio frequency currents but open circuits for heating energy supplied through power amplifier 40. For a similar reason, condensers 35 have been inserted in one of the jumpers short circuiting the wires 39, 38.

The flow of heating energy through the antenna structure and, of course, a similar flow through the reflector structure may be traced as follows. Heating energy from transmission line 20 passes through conductor 2|, conductor 30, upper portion of jumper I0, conductors 2, 38 and 5, lower portion of jumper l0, conductors 32, 21 and. 32 to the other antenna unit comprising conductors 4 and 8 back through the upper portion of jumper l2 and conductors 30 and 29 to transmission line 20.

To provide for the series energization of both antenna and reflector with heating energy and the parallel energization thereof with high frequency energy, condensers 4B are placed in the transmission line 20 leading to the antenna A which condensers oifer little or no impedance to currents of radio frequency. A radio frequency choke 48 is, however, connected diagonally across condensers 46 to allow of the serial flow of heating energy through the antenna and reflector structures.

In the event that only a small amount of heating power is available an arrangement such as shown in Figure 3 is used to good advantage. Heating energy is applied to either the antenna or reflector from a power transformer 48 by means of switch 5!] connecting the secondary of the power transformer to either the sleet melting lines 52 leading to the antenna structure or to the sleet melting lines 54 leading to the reflector structure. Heating energy is applied to the tuning conductors 28 and flows serially through the conductors of each unit and in parallel through the units. This system, however, does not provide for the heating of the high frequency lines, which, may be heated by supplying energy, as shown, through high frequency chokes 42 to the high frequency transmission line 44 and thence through the impedance matching circuit iii to the high frequency supply lines for both the antenna and reflector structures.

In the event that a more concentrated system is to be used, thus, for example, the side by side placing of similar antenna and reflector structures or the superimposition of the same, the features of the present invention may, of course, be embodied therein without departing from its scope as defined by the appended claims.

Having thus described my invention, what I claim is:

1. An antenna system having, in combination, diverging radiators, angularly disposed with respect to each other and disposed in a plane, a similar pair of diverging radiators located in a parallel plane, the correspondingly placed radiators of said pairs being parallel to each other, conductors respectively connecting together only one of the ends of said correspondingly placed parallel radiators, a pair of connections coupled to each pair of said parallel radiators at the other ends thereof, a condenser bridging each of said pairs of connections, a line directly coupling together one wire of one pair of connections with one wire of the other pair of connections, the other wires of said pairs of connections being capacitively coupled together, a two Wire transmission line, a condenser bridging said transmission line, conductive paths between said transmission line and diiferent Wires of said pairs of connections, a source of heating current conductively coupled to said transmission line whereby said pairs of radiators are serially connected thereto, high frequency apparatus capacitively coupled to said transmission line and simultaneously with said source of heating current whereby said pairs of radiators are eifectively in parallel with respect to said apparatus, and choke coils for preventing the flow of high frequency current to said heating source.

2. An antenna system having, in combination, diverging radiators angularly disposed with respect to each other and disposed in a plane, a

similar pair or" diverging radiators located in a parallel plane, the correspondingly placed radiators of said pairs being parallel to each other, conductors respectively connecting together only one of the ends of said correspondingly placed parallel radiators, a pair of connections coupled to each pair of said parallel radiators at the other ends thereof, a condenser bridging each of said pairs of connections, a line directly coupling together one wire of one pair of connections with one wire of the other pair of connections, the other wires of said pairs of connections being capacitively coupled together, a two wire transmission line, a condenser bridging said transmission line, conductive paths between said transmission line and different wires of said pairs of connections, an identical antenna structure spaced away from said first antenna system an odd multiple of a quarter wave length, said two wire transmission line of said first antenna system being coupled to the two wire transmission line of said second antenna, one wire of one transmission line being directly connected to one wire of the other transmission line and the other wires of said transmission lines being capacitively coupled together, a source of heating energy conductively coupled to both said two wire transmission lines whereby all of said pairs of radiators are serially connected together, high frequency apparatus capacitively coupled to said transmission lines and simultaneously with said source of heating energy whereby said pairs of radiators are effectively parallel with respect to said apparatus, and reactances for preventing the flow of high frequency current to said heating source.

PHILIP STAATS CARTER. 

